Dec 28, 2023 - Energy & Environment

2024 may be the hottest year in recorded history

Global average temperature anomalies, 1850-2023
Data: NOAA; Note: Uses 1901-2000 mean, 2023 data through November; Chart: Simran Parwani/Axios

2024 may be even hotter than the "gobsmackingly" hot 2023, which featured extreme — and often deadly — weather and climate events around the globe.

Why it matters: A hotter 2024 would lend credence to the hypothesis that global warming is accelerating.

"If things follow the normal pattern, 2024 should be a bit hotter than 2023. But 'the normal pattern' may not exist anymore," said Andrew Dessler, a climate scientist at Texas A&M University.

  • "In any event, it's certainly going to be one of the hottest years in the record."

The big picture: The combination of human-caused global warming from the burning of fossil fuels for energy, along with deforestation, plus other factors like a naturally occurring El Niño, have boosted 2023's record warmth, stunning many in the scientific community.

Where it stands: There is a strong El Niño event in the tropical Pacific Ocean. Such phenomena feature warmer-than-average ocean temperatures near the equator, particularly from the Central Pacific eastward, along with shifts in weather patterns that can reverberate globally.

  • El Niño events also boost surface temperatures on top of the human-driven trend, as occurred in 2016, the current record-holder for the warmest year on record.

The intrigue: Deke Arndt, who heads NOAA's National Centers for Environmental Information (NCEI), likens the course of human-caused and naturally variable warming to riding an escalator.

  • During an El Niño, the escalator rider takes a step up, representing a bigger temperature shift. Other times the rider may stand still but is nevertheless ascending the temperature curve, just at a slightly slower pace.

Context: Typically, El Niño events have a time delay, with their biggest influence on global average temperatures coming a few months after ocean temperatures peak.

  • This would suggest that 2024 stands a good chance of being warmer than 2023 since the ongoing El Niño will be most influential in at least the first part of 2024.
  • A strong-to-borderline historically strong El Niño is present now, but it's unclear how quickly it will fade in 2024. If it lasts through spring and into early summer, then next year should top 2023 for the warmest title, climate scientists told Axios.

Yes, but: Michelle L'Heureux, NOAA's top El Niño forecaster, told Axios this one may fade next spring and give way to a La Niña event — which would feature cooler than average waters in the same regions of the Pacific.

  • If this happens, 2024 could be a top 5 warmest year without overtaking 2023.

What they're saying: Gavin Schmidt, who heads NASA's Goddard Institute for Space Studies in New York, estimates that 2024 temperatures will eclipse 2023's records. He based this on long-term trends and the intensity of the El Niño conditions predicted during December through February.

  • Others, however, are more skeptical.
  • "During the typical first year of an El Niño, we see a global temperature spike in the last few months of the year followed by very warm conditions during the first months of the following year," said Robert Rohde, a scientist at Berkeley Earth, an independent group that tracks global temperatures.
  • But given the staggering temperature spike seen this year and rapid flip to a strong El Niño, among other factors, Rohde said: "I think there is a better than even chance that 2024 defies the typical expectations, and actually ends up a bit cooler than 2023."

Of note: Since this is the first year of the strong El Niño, one would expect next year to see the temperature peak. It could make this year analogous to 2015, for example, with the record broken in 2016, climate scientist Zeke Hausfather says.

  • "This year has been weird enough — and exceptional levels of global surface temperature have been seen so early on the El Niño development — that I'm a bit reluctant to assume it will necessarily follow the same pattern we've seen in the past," Hausfather adds.
  • "At this point, I'd still probably give better than even odds that 2024 is warmer than 2023, but only just."

The bottom line: "The only really important question is, 'How many more years like this we have to have before the reality of how bad climate change is breaks into the public's consciousness?'" asked Dessler, of Texas A&M.

Go deeper:

El Niño's Global Impact

Data: Global warming may be accelerating

Photo Essay: The Earth's warmest year on record

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